Reliance on synthetic auxin herbicides (HG 4) has increased following the introduction of dicamba and 2,4-D resistant soybean. A common question among users of these products is: “If I use one trait repeatedly and select for resistance to that herbicide, will I be able to switch to the other trait to control the resistant population?”
The plentiful rain in September has provided ideal conditions for establishment of winter annual weeds, thus many no-till fields will have dense stands of these weeds going into winter (Fig. 1). The wetter springs we have encountered recently complicate getting spring burndown applications made in a timely matter.
Problems caused by unfavorable conditions this season have resulted in greater than normal weed escapes. These weeds may reduce crop yields and definitely will contribute to future weed problems via new seed. While it is too late to protect crop yields, a common question is whether herbicides can be used to reduce the quantity of viable weed seed produced by weeds. While there is no simple answer due to the many different scenarios across the state, in most situations late-season applications are not warranted.
